Search a number
-
+
640451 = 791493
BaseRepresentation
bin10011100010111000011
31012112112102
42130113003
5130443301
621421015
75305130
oct2342703
91175472
10640451
113a81a9
1226a76b
13195686
14129587
15c9b6b
hex9c5c3

640451 has 4 divisors (see below), whose sum is σ = 731952. Its totient is φ = 548952.

The previous prime is 640421. The next prime is 640457. The reversal of 640451 is 154046.

It is a happy number.

640451 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 154046 = 277023.

It is a cyclic number.

It is not a de Polignac number, because 640451 - 214 = 624067 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640451.

It is not an unprimeable number, because it can be changed into a prime (640457) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45740 + ... + 45753.

It is an arithmetic number, because the mean of its divisors is an integer number (182988).

2640451 is an apocalyptic number.

640451 is a deficient number, since it is larger than the sum of its proper divisors (91501).

640451 is an equidigital number, since it uses as much as digits as its factorization.

640451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91500.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 640451 is about 800.2818253590. The cubic root of 640451 is about 86.1976255575.

Adding to 640451 its reverse (154046), we get a palindrome (794497).

It can be divided in two parts, 64045 and 1, that added together give a palindrome (64046).

The spelling of 640451 in words is "six hundred forty thousand, four hundred fifty-one".

Divisors: 1 7 91493 640451